Critical Listening Room

Despite the marvellous electronic advances in digital workstation, sound must eventually travel the acoustic analog path from loudspeaker to our ears. Between these two elements there is the ambience which can makes “Acoustic Distortions”. We know electric distortions, but acoustic distortions are usually unknown and neglected. Acoustic distortions effects are difficult to describe but some times they are devastating and easy to identify if a listener is in the condition to hear them. In the figure below you can see an equivalent circuit to acoustic distortions. The signal from a DAW or mixer is fed to a parametric or graphic equalizer, then to a digital delay unit and finally to an amplifier and loudspeaker. Try to imagine if this circuit were to be inserted, without your knowledge, into your recording- mixing chain. The circuit would boost 71, 142, 213 Hz by 10 dB, and inserts 4ms, 7 ms, 9 and 10 ms of delay.

The engineer would mix the sound product and subconsciously attempt to adjust for these effects. Imagine the surprise of the engineer when he comes to realize all this without his knowledge and plays back the mix with the equalizer and digital delay switched off! The most relevant point is transferability. The audio product created in a recording studio needs to sound similar in a wide range of listening rooms. Thus, the audio product must be transferable to these different listening environments. This means that a recording engineer must be aware of the acoustical signature of the room he/she is working in, so that the signature of the “room” is not embedded into the audio product. Many project studios and some professional studios have their own acoustical signature but, for them there is the last chance to fix this anomalies: the mastering studio. So, at this point, you can clearly understand that the mastering studio can not have the last Chance!! That is way the absolutemastering critical listening room is free from acoustical signature. The critical listening room was Designed with the contribution of Aalborg (Denmark) acoustic university and as we can see from the next graphics it shows an excellent acoustic behaviour.

Fig 2 we can see the ETC ( Energy Time Decay) of the room. It is clear the gap between the direct sound and the reflect sound and we have a very good control of the early reflections which generate acoustic distortion on the perception of the tone and stereo image.

Fig 3 we have the frequency response (obtained using a spectrum analyzer and pink noise) of the monitor system.

As you can see the accuracy is ±2db, considering that the accuracy of the monitor system is ±1db we can clearly say that “there is no signature of the room”.